Dynasafe R&D in Demilitarization Dynasafe Demil Systems
Gene Wells Global Demilitarization Symposium 2015-12-08
Mission Statement
Our Vision Dynasafe protects mankind from threats caused by explosive devices and hazardous materials.
Our Mission Dynasafe makes the world a safer and a cleaner place. Dynasafe is committed to providing an integrated and all-encompassing DISPOSAL VALUE CHAIN; from surveying and search, to location, clearance, containment and transport, up to disposal and even to the recycling of explosive devices and hazardous materials.
Dynasafe R&D in demilitarization
• The need for customization
• Evolving applications for Calculations
• R&D tools for fast, reliable and safe product development.
• Conclusions
Customer need is the driver for efficient R&D tools
• Customer requirements often look very different in terms of destruction objects, capacity, budget etc.
• To accommodate this need versatile, flexible and modular solutions are necessary.
• It is sometimes advantageous to customize a solution for a better fit and optimize to specific requirements.
• The Dynasafe R&D toolbox: • quickly work out new solutions, concepts, layouts etc. • rapidly and accurately determine strength and durability of critical
system components or assemblies (Loading Systems, Detonation Chambers, Building Structures etc.)
• analyze waste stream process flows, mass balances, etc.
The Dynasafe Calculation Toolbox
• Reliable FEM calculations are important to understand strength and durability.
• Ultimately, this transfers to safety at destruction sites.
• Dynasafe has 25 years of experience in developing safe and productive solutions for both protection and demilitarization systems using process knowledge gained and an evolving calculation methodology.
• The process begins with the understanding of calculation fidelity with respect to protection systems. They are exposed to the most extreme loads in terms of shock and fragmentation wear.
• This fidelity can then be used to accurately determine strength and durability of demilitarization systems.
Using Protection systems as the basis: The DynaSEALR X12
Test rig
The X12
FE-model of the X12
The most relevant load carrying parts
L=1500 mm, D=1300 mm, T=30 mm, W=2800 kg
Vessel Locking ring Cover
FE-model cont’d.
Simplify and mesh MAP a 15° section of the Locking Ring Teeth
FE-model cont’d
Cut away view of the meshed locking mechanism
FE-model cont’d
The complete model with attachments. The model consists of 800,000 volume elements with 99.6 % hexas and 0.4 % pentas
Simulation setup
Spherical charge of 8.0 kg TNT equivalent in the center
Fixed boundary conditions at the bottom feet
High strength steel with yield strength 900-1000 MPa
4 simulated strain gauges
1 2 3 4
Blast load technique, method 1
Axisymmetric mapping to 3D The explosive blast load is done in a separate axisymmetric fluid Multi Material Arbitrary Lagrangian Eulerian (MMALE) simulation. The pressure is recorded on the fixed boundary (red line) and a script is used to map the blast load to a 3D structure simulation. This runs approximately 3 hours on 16 processors. Suitable for axisymmetric chambers (which is very typical)
Blast load technique, alternative method
Fluid-structure coupling in 3D
The explosive blast load is done directly in the structure simulation using 3D MMALE with a fluid-structure coupling.
24 hours on 16 processors. The CPU time is significantly reduced by using a half model due to symmetry or remove the fluid after 5-10 ms.
This technique can be employed with any geometry.
Results from a CFD view
Axisymmetric blast load simulation, 8kg TNT, first 2 ms
Pressure fringe scale 0-0.02 GPa (0-200 bar)
Results from structural dynamics view
Structure simulation, first 10 ms
The vessel and cover ends are moving 5-10 mm. Unscaled displacements in the video.
Results from structural dynamics, cont’d
Structure simulation, first 10 ms
The displacement is increased 10 times
Results comparison, method 1 & 2
Strain curves at the vessel end (gauge 1)
Peak values ≈ 0.6 %
Axisymmetric mapped to 3D Fluid-structure coupling in 3D Test curves in red Simulated curves in blue
RESULTS
Strain curves at the locking ring (3)
Peak values ≈ 0.1 %
Test Sim
Axisymmetric mapped to 3D Fluid-structure coupling in 3D
Conclusion from FE-simulations
The simulation and the measured effects are well inline with each other.
Fragment damage calculations
• Tool for determining fragment damage has been developed.
• Multiple layers can be defined and the prediction accuracy is very high.
Transfer and Application
The tools developed for predicting the effects of a blast on a Protection System Chamber are then applied to the cold Detonation Chambers or adapted to the hot Detonation Chambers used in demilitarization
1. CFD simulation with blast data for specific explosives is used to create the load.
2. The dynamic response will show the stresses and strain experieced by the vessel. Highly stressed ROI are mesh-refined to capture the correct.
3. Fatigue are calculated for all ROI according to a selected standard.
R&D tool: Fatigue
FEM-simulations for strength and durability
GPa
R1 R2
R4 R3
R5 R6
R7
R8
B1
R9
Table of max effective stress [MPa] / strain [%]
Estimated fatigue life [detonations]
Evaluations of stress, strain and fatigue life. R1-R9, B1 are evaluation points.
Comparison of predicted vs. acutal wear in an operational SDC1200
Predictions
Actual wear
Wear profile along height Wear contour
Wear distribution 3D representation
Laser scanning, for accurate wear measurements
Another useful tool: Process analysis
• In-house developed program during 10 years. A multiphysics simulation tool that combines: gas composion, thermophysics, thermodynamics chemical reactions, thermal decomposition, condensation/evaporation gas/liquid/solid flows, structural heating and cooling
Process analysis tool, cont’d
| Slide 31
Process analysis tool, cont’d
December 15 | Slide 32
Mass and energy balance tool
Detonation Chamber is normally coupled with an Off Gas treatment (OGT) system that is suitable for the Customer’s needs.
Dynasafe designs OGT Systems in-house
Dynasafe has developed a Microsoft Excel based Mass and Energy balance tool for designing the process.
Mass and energy balance tool, cont’d.
Inputs
Define Process Feed composition Process parameters
Background calculations
Reaction stoichiometry Removal efficiencies Mass balance Energy balance
Outputs
Stream flows, composition Pressure, Temperature Utilities requirements
Spray dryer
Bag house filter
Scrubber
s
HXr
Condensate tank
Bleed water tank
COB and
DeNox ID fan
Stack salts Salts,
dust additives
Process water tank
Off gases with H2O in gas phase
Condensate
Water with salts and impurities
Solid residues
Filters
Dust, heavy metals
General process flow, Chemical Weapons
ARB 20/03/2015 Only for illustation
From SDC
To Atmosphere
Potable water
Typical OGT
Thermal Oxidizer
Conclusions
• Dynasafe has the expertise and tools to quickly develop purpose built solutions to meet specific Customer needs. These solutions are robust and predictable in terms of characteristics for strength, durability, process flow, etc.
• This translates into projects with low technical, financial and temporal risks.
• And most importantly, the conservative approach means safe systems in the field!
| Slide 38
Thank you!